Xfitem = [gauss_sample([0;0], [1,0; 0,1], 100), ...
           gauss_sample([5;0], [1,0;0,1], 100), ...
           gauss_sample([0;5], [1,0;0,1],100)]';
mixture = gmm_fitem(Xfitem, 3);

figure
hold on
scatter(Xfitem(:,1), Xfitem(:,2), 'x', 'k');
plot_gauss_2d(mixture.mu{1}, mixture.sigma{1}, 1, 'r');
plot_gauss_2d(mixture.mu{2}, mixture.sigma{2}, 1, 'g');
plot_gauss_2d(mixture.mu{3}, mixture.sigma{3}, 1, 'b');
